Armature adjustment for electromagnetic operated switches



Aug. 15, 1950 Filed July 26, 1946 E. ZOERLEIN ARMATURE ADJUSTMENT FOR ELECTROMAGNETIC OPERATED SWITCHES 3 Sheets-Sheet 1 EMIL ZOERLEIN.

I INVENTOR. 61 fi ATTQRNEYl Aug. 15,1950 E. ZOERLEIN 2,519,093

ARMATURE- ADJUSTMENT FOR ELECTROMAGNETIC OPERATED SWITCHES Filed July 26, 1946 s Sheets-Sheet. 2

2/ X I /O I I I 3 K J\ M 46 v MIL ZOERLEIN INVENTOR. 1 1g. 4' 676 zr fih.

ATTORNEYS.

OPERATED SWITCHES Aug. 15, 1950 Filed July 26, 1946 VOLTAGE CCWTROL COIL ' CAN;

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6? Q )4 BY ,& f6! 4 ATTORNEYS Patented Aug. 15, 1950 UNITED STATES PATENT" OFFICE ARMATURE ADJUSTMENT FOR ELECTRO- MAGNETIC OPERATED SWITCHES tion of Delaware Application July 26, 1946, Serial No. 68691185 4 Claims. I.

This application is concerned with a generator control designed. especially to regulate the output of an automotive generator, although it is applicable wherever a. battery is to be charged from a generator whose speed must vary over wide limits.

Gontrols: for automotive generators should serve at least three distinct purposes. They should closely regulate. the voltage oi the genorator; they should limit the current output of the generatorso that it is kept within the capacity or the. machine; and. they should promptly disconnect the; battery from the generator when the generatorvoltagev 'falls below normal battery voltage to prevent discharge of the battery through the generator. These three functions are each carried out by an individual element in the control assembly. The: voltage control unit functions by inserting a resistance in the field circuit of the generator when the voltage becomes too: high, the current control similarly limits the: output of" the generator by inserting a. similar resistance in the field circuit when the current output becomes excessive and the battery cutout is simply a relay arranged so as to permit passage of the current in one direction only, that is. from the. generator to the. battery.

To compensate for irregularities inevitable in manufacture and: to adjust for wear, each of these individual units must be adjustable. To obtain the best. performance. of the entire electrical system, each of these adjustments must be accurately made having once been made, mustbe retained'ior long periods of service.

It an object: of this invention to provide a generator control in which the necessary adjustmentslare readily made. It is a further object of this invention to provide adjustments which are stable in service.

With these and other objects in: View, the invention comp-rises the arrangement. construction and combination of the. various. elements of the structure described in the specification, claimed in the claims and illustrated in the accompanying drawings, in which:

Figure I is-a plan view of the control with the cover removed.

Figure 2- is a front elevation of the control with the. cover removed.

Figure 3 is an elevation, partially in section, of the voltage control unit, taken on line 3--3 in Figure 2.

Figure 4 is an elevation, partially in section, of the battery cutout, taken on line 4 4 Figure 2.

Figure 5 is a schematic wiring: diagram of the control.

Figure 1 is: a plan elevation of: the: control. The control isv built upon a. pressed steel base plate provided with mounting means. H and ground connection [2. Mounted upon base plate HIE is the voltage control t3, the. currentcontrol M and battery cutout I5. Electrical connecting lugs l6, l1 and I8: are provided respectively for connection to the generator armature, generator field and the battery.

The voltage control unit is shown in section in. Figure 3'. This control unit is built around a heavyframe [9 which is bolted tobase plate: l6, but. electrically insulated. therefrom by insulating plates 28. and 21 and an insulating collar 22*. This: frame ['95 is electrically connected to. armar ture connection It by strap 23. Voltage control coil 24. with a. central iron core is mounted on frame $9. This is a high resistance coil: of many turns off fine wire and is connected to: the generator through frame I! and to ground To minimize variations. in performance due to; temperature fluctuations; a portion of voltage. control coil 2G is made from a. copper nickel alloy commercially known as Advance. This type of alloy is chosen since the composition can be. adj'usted to give a temperature coefficient of resistance which approaches zero orris negative. Maggnetic. shunt 25 extends from the upper end of the iron coil core; to. a point near the top. rear end of frame l9. Magnetic shunt 2-5. is made of an iron nickel alloy which is characterized by a rapid drop. in magnetic permeability at low temperatures. Thus at low'temperatures the generator voltage would be controlled at a higher value than at ordinary temperatures. Contact support 2'1 is. bolted to the front of frame [9, but electrically insulated therefrom by insulating plate 28 and insulating collar 29; Ctontsmt support 21 supports contact point 30: through. screw 3| and lock nut 32'. Contact point 30. coacts with contact point 33'. which is mounted on armature 215 through. cushion spring 34. Armature 26'. is secured to framev I 'S! through spring 35 which is bolted between plates 38 and 31'. Brass rivet 3.8% serves to prevent actual contact between arm ature M5 and the core ofthe-voltage control core. Armature 26 is. biased upwards by spring 39 Which passesthrough aperture 40 in contact support 21 and; which rests upon eccentric 4i. Eccentric 4! is provided with an adjustment slot '42 designed to receive a screw driver or similar instrument. This eccentric is rotatably mounted in frame 19 and swaged into place in such a 3 manner that a very substantial torque is required for rotation. The fact that the head of eccentric 4| is not concentric with the mounting makes it possible to adjust the tension in spring 39 by rotation of the eccentric. This eccentric is provided with a shoulder 43 so that any burr produced in cutting slot42 will not interfere with the adjustment.

Current control unit l4 will not be described in detail since it is mechanically identical with voltage control unit l3. It differs therefrom electrically in that its sole winding consists of comparatively few turns of heavy wire inserted directly into the generator battery circuit; It differs from the voltage control magnetically in that the magnetic shunt is not present.

The structure of the battery cutout is shown in detail in Figure 4. Frame 44 is bolted to base plate Ill, but electrically insulated therefrom by insulating plates 20 and 2| and insulating collar '45; Frame 44 is connected with battery connection l8 through connector 46. Frame 44 supports an iron core upon'which are'wound three coils. The outer coil is a continuation of the core f the current control unit and'consists of a few turns of coarse wire which is, of course, in series with the generator battery circuit. Under this coarse coil is a coil comprising many turns of fine wire which connects the generator side of the battery cutout 15 to ground. The inner coil resembles the voltage control coil in that it con tains, in addition to copper wire, a high resistance copper-nickel alloy section. This coil connects the generator side 'of the battery cutout and -ground. Armature 41 is mounted on frame 44 through spring 48. Armature 41 is biased in an upward direction by spring 49. The tension on spring 49 is adjusted by knurled nut 50. This "knurled'nut 50 is secured against accidental rota- 'tion by spring clip Secured to the forward 1 :side of frame is contact support 52 carrying contact 53' andlug 58 (Figure 2) to which is secured the lead to both cutout coils.

- Armature 41 carries springmember 54 upon which is mounted contact 55. The face of this "contact is spherical to aid in the achievement of good electrical contact despite misalignment of other parts of the instrument. Upward motion of armature 41 and spring member 54 is limited by retainer 56, which is secured to the forward side of the frame 44. The forward end of armature 41 and spring member 54 are held together by rivet 51. 'This rivet is of non-magnetic material and serves at least two purposes. .That portion projecting beneath armature 4'! serves to limit the movement in a downward direction of'the armature by contact with the frame and also prevents actual contact between the armature and frame. :Such contact would tend to cause sticking of the pointstogether. The underside of the head of rivet 51is flat and parallel with the face of'spring member 54. During assembly care is taken to drive rivet 51 so that a clearance of the order of 0.009 inch is left between the underside of the rivet head and the top of spring member 54. As

' armature 41 is attracted towards the iron core in response to rising generator voltage, contact .is first made with spring member 54 tightly resting upon armature 41. As downward motion of the armature continues, springmember 54 flexes through its entire length while, the clearance 4 between spring member 54 and rivet 51 is being taken up. When this clearance has been taken up, spring member 54 flexes only forward of rivet 51. The combined action of rivet 51 as a pivot and the pivot spring 48 upon which armature 41 moves results in a slight wiping action of contact 55 over contact 53 which gives a good. electrical contact and minimizes any tendency towards welding or sticking.

Figure 2 is an elevation of the control. It is thought that the significance of this drawing is apparent from the above discussion and that further explanation is not necessary.

Figure 5 is a schematic wiring diagram of the control. In this drawing the path of the generator current to the battery is shown in heavy lines and the ancillary wiring in light lines. The purpose of the leakage resistance is to help take up any voltage surges incident to the interruption of the inductive field circuit by the controls.

' I claim as my invention: l

l. A voltage control for a vehicle generator comprising a generally U-shaped frame, an eccentric spring adjustment secured to one leg of the U, a temperature compensated shunt coil and axial iron core mounted in the central portion of the U, and an armature assembly mounted on the other leg of the U, the armature assembly comprising an armature, a flat spring hinging the armature tothe frame, a contact carrying spring and a spring serving to bias the armature away from the iron core, said biasing spring resting upon the. eccentric adjusting means and being adjustable thereby.

2. A current control for a vehicle generator comprising a generally U-shaped frame, aneccentric spring adjustment secured to one leg of the U. a series coil and axial iron core mount.- ed in the central portion of the U and an armature assembly mounted on the other leg of the U, the armatureassembly comprising an armature, a flat spring hinging the armature to the frame, a contact carrying spring and a spring servin to bias the armature away from the iron "core, said biasing spring resting upon the eccentric adjusting means and being adjustable thereby.

3. The structure in claim 1 in which the'adjustment comprises a rotatable pin carrying an eccentrically mounted; shouldered and slotted head, said pin being swaged'into frame so. that a substantial torque is required for its rotation.

4. The structure in claim 2 in which the adjustment comprises a rotatable pin carrying an eccentrically mounted, shouldered and slotted head, said pin being swaged into frame so that a substantial'torque is required for its rotation.

' EMIL ZOERLEIN.

REFERENCES CITED y The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 727,611 Gilbert et al. May 12, 1903 1,398,463 Lee Nov. 29, 1921 1,411,311 Sullivan Apr. 4, 192-2 1,576,768 London Mar. 16, 1926 1,591,133 Kent July 6, .1926

1,785,887 Chryst -Dec. 23, 1930 2,037,118 Chubbuck Apr. 14, 1936 

